1. Field of the Invention
The present invention relates to a vacuum cleaner in which exhaust air is not discharged out of a cleaner main body but is returned into a suction port body to be recirculated.
2. Discussion of the Related Art
As the vacuum cleaner of this type, for example, one shown in FIG. 18 has been disclosed (see Japanese Utility Model Publication No. 39-36553).
Referring to FIG. 18, a vacuum cleaner includes a cleaner main body 1; a filter 2 disposed in the cleaner main body 1; a dust collecting chamber 3 formed in the filter 2; an electric fan 4 disposed in the cleaner main body 1 in such a manner that the suction side thereof is communicated to the dust collecting chamber 3; a suction side connecting port 5 provided in the cleaner main body 1 in such a manner as to be communicated to the dust collecting chamber 3; an exhaust side connecting port 6 provided in the cleaner main body 1 in such a manner as to be communicated to the exhaust side of the vacuum cleaner. A suction port body 7 is connected to the cleaner main body 1 via a hose and a connecting pipe 8.
The suction port body 7 has an exhaust air passage 9 for blowing exhaust air from the front side to the underside of a suction port 7a, and a suction air passage 10 for sucking dust from the suction port 7a. The connecting pipe 8 has an inner/outer dual structure of an inner pipe 8a and an outer pipe 8b. A suction air passage 11 in the inner pipe 8a is communicated to the suction side connecting port 5 and the suction air passage 10, and an exhaust air passage 12 between the inner pipe 8a and the outer pipe 8b is communicated to the exhaust side connecting port 6 and the exhaust air passage 9.
In such a vacuum cleaner, dust sucked together with air from the suction port 7a is sucked in the dust collecting chamber 3 via the suction air passages 10 and 11 and is caught by the filter 2. On the other hand, the air cleaned by the filter 2 is guided via the electric fan 4 into the exhaust air passage 12 and the exhaust to air passage 9 a front side of the suction port 7a. The air blows dust on a carpet or cleaning plane 13 into an intake side of the suction port 7a. The dust thus blown is sucked again in the suction air passage 10. The air is thus recirculated.
Vacuum cleaners shown in FIG. 19. (see Japanese Laid-open Utility Model No. 50-97269) and FIG. 20 (Japanese Laid-open Utility Patent No. 51-95266) are configured so that, when an electric fan 515 in a cleaner main body 514 is operated, a suction negative pressure caused by operation of the electric fan 515 is applied to a suction port body 518 via a dust collecting chamber 516 in the cleaner main body 514 and a suction pipe 517, to suck dust together with air from the suction port body 518. The dust sucked in the suction port body 518 is sucked into the dust collecting chamber 516 via the suction pipe 517 and is caught by a filter 519. The air cleaned by the filter 519 is exhausted in an exhaust chamber 520 disposed behind the electric fan 515, and is guided back to the suction port body 518 via an exhaust pipe 521. The air thus guided is blown and sucked together with dust on a carpet or cleaning plane 522 in the suction port body 518. The air is thus recirculated.
Incidentally, the vacuum cleaner shown in FIG. 18 has a connecting structure such that the end surfaces of the connecting ends of the connecting pipe 8 and the suction port body 9 are in abutment with each other. In order to enhance airtightness of an abutted portion between the end surfaces of the connecting ends of the connecting pipe 8 and the suction port body 9, flanges of both the connecting ends are rigidly fixed to each other over the entire periphery via C-shaped fixtures F.
Such a structure, however, has a problem. Since the thickness of each of the end surface portions of the connecting ends of the connecting pipe 8 and the suction port body 9 is small, it is very difficult to simply ensure airtightness, and further the suction port body 7 cannot be replaced by another suction device or cannot be, if it fails, exchanged for a new one.
The vacuum cleaner shown in FIG. 18 has another problem. Since the vacuum cleaner shown in FIG. 18 is configured such that the suction air passage 11 and the exhaust air passage 12 are provided in the connecting pipe 8 having the inner/outer dual structure, it is impossible to remove the exhaust air passage 12 from the suction port body 9 and separate it from the suction air passage 11, and use the separated exhaust air passage 12 for blowing dust off the cleaning plane. The vacuum cleaners shown in FIGS. 19 and 20 have a different problem. Since the vacuum cleaners are configured such that the suction pipe 517 and the exhaust pipe 521 are juxtaposed and integrated with each other, it is impossible to separate the exhaust pipe 521 from the suction pipe 517 and the suction port body 518, and use the separated exhaust pipe 521 for blowing dust off the cleaning plane.
The vacuum cleaner shown in FIG. 18 has also an inconvenience. Since a fan 14 rotated by exhaust air from the exhaust air passage 12 is provided in the suction port body 7 and the fan 14 is configured such that brushes 16 are rotated via a pulley mechanism, the connecting pipe 8 is not provided with a handling side operating portion for operating a turn-on/off switch of the fan 14 and the electric fan 4.
On the other hand, there is known a vacuum cleaner of a type in which a flexible hose having a spirally corrugated structure extends from a cleaner main body, and a handling side operating portion for controlling an electric fan is provided at a leading end portion of the hose.
A suction port body is connected to an end of the hose via an extension pipe, wherein the turn-on/off switch, the output, and the like of the electric fan can he controlled by a key-operation of the handling side operating portion while the suction port body is moved. In the conventional vacuum cleaner of this type, however, a lead wire and the like extending from the cleaner main body to the handling side operating portion is spirally buried along an accordion-like outer peripheral portion of the hose.
Accordingly, if the above hose is applied to the vacuum cleaner shown in FIG. 18, there arises a problem that, since the lead wire is spirally wound on the hose, the weight of the hose portion is not reduced and it takes a lot of labor to manufacture the hose. Further, if the lead wire is provided in the suction air passage 11, there occurs a problem in that the sucked dust is caught by the lead wire and thereby the lead wire may be disconnected or the suction air passage may be clogged with the sucked dust.